California voters were rejecting a ballot measure to cut the time lawmakers could serve in the Legislature by two years but give current incumbents a windfall term extension, according to early returns.

With about 40 percent of the precincts reporting, 52 percent of voters were opposed to the measure while 48 percent were in favor.

Proposition 93 was proposed by the Democratic leaders of the Legislature and supported by Republican Gov. Arnold Schwarzenegger, who said the state's current term limits are too restrictive.

Lawmakers now can serve a total of 14 years - no more than six years in the Assembly (three two-year terms) and eight years in the Senate (two four-year terms) - according to rules set by state voters in 1990.

Under Prop. 93, they would be allowed to serve a total of 12 years - either in one house or the other, or a combination of the Assembly and Senate.

Opponents called the initiative a power grab because it also would allow legislators who would be termed out of office this year under current rules to serve an additional six years in the Assembly or an extra four years in the Senate.

Two of those lawmakers are the leaders of the Legislature - Assembly Speaker Fabian Núñez, D-Los Angeles, and Senate leader Don Perata, D-Oakland.

While supporters and opponents of Prop. 93 carried on a spirited campaign, it took place largely outside the attention of most voters, who were not aware of the measure or its ramifications until the weeks before the election.

A Field Poll released Sunday found support for the measure was waning with 46 percent of likely voters opposed, while just 33 percent were in favor with 21 percent undecided. That's a big change from a poll taken in October when 49 percent said they would support the proposal and 31 percent said they were opposed, with 20 percent undecided.

In December, a Field Poll found just 25 percent of voters had heard or seen anything about the proposal. When voters were read a summary of the measure, 50 percent said they would support it.

But in January, more than twice as many voters were aware of the measure and were split equally for and against, with 22 percent of likely voters undecided, the Field Poll found.

Supporters, including former state Controller Steve Westly, said the current system forces lawmakers to begin considering their next office almost immediately after getting elected. Allowing lawmakers to spend all their time in one house, proponents said, would give them time to develop expertise on critical issues.

The opposition was led by Insurance Commissioner Steve Poizner, who contributed $2.5 million to defeat the measure. Poizner said he was not necessarily opposed to tweaking the current term rules, but he took exception to the way Prop. 93 would benefit current incumbents.

Perata, for example, would be able to run for another term in the Senate. Núñez would be eligible for three more Assembly terms.

The opposition campaign raised about $7 million, including about $2 million from the state prison guards union and $1.5 million from U.S. Term Limits, a Virginia group in favor of term limits.

Supporters raised about $13 million, most of it from labor groups and corporations.

Prop. 93

An amendment to the state Constitution that revises term limits for state legislators. Under current law, legislators can serve a total of 14 years - six in the Assembly and eight in the Senate. The initiative would allow them to serve a total of 12 years, all in one house or a combination of both houses.